Concentrated liquid compositions of urease inhibitors for nitrogen sources

Abstract

The present invention relates to increasing and/or maintaining nitrogen content in soil by administration of nitrogen sources particles coated with urease inhibitors. In one embodiment, urease inhibitors are dispersed in an improved organo liquid delivery system at concentration levels of 60-95%. In another embodiment, urease inhibitors were applied in a non-aqueous, organo liquid delivery system coating nitrogen sources particles utilizing simple blending equipment at temperatures of 20°-70° C. Another embodiment discloses dry, flowable nitrogen sources coated with a urease inhibitor which can be administered directly to the soil, to a dry natural and/or a manmade fertilizer or to a liquid fertilizer which provides for the reduction of nitrogen loss from the soil. In another embodiment, a composition of urea and <0.2% dimethyl sulfoxide improves the crush resistance of the urea particles.

We claim: 
     
       1. A dry, flowable fertilizer composition, wherein the dry, flowable fertilizer composition comprises:
 a) one or more particulate nitrogen sources, the one or more particulate nitrogen sources heated between 60° C. to 80° C.; and 
 b) a solid coating composition that is heated to a temperature ranging from 50° C. to 70° C. to obtain a heated liquid, wherein the heated liquid is applied onto the one or more particulate nitrogen sources, wherein: 
 the heated liquid comprises:
 i) N-(n-butyl) thiophosphoric triamide (NBPT) ranging from 75% to 95% by weight of said solid coating composition and 
 ii) dimethyl sulfoxide (DMSO) ranging from 4% to 24% by weight of the coating; 
 
 wherein the dry, flowable fertilizer composition comprises the solid coating composition homogeneously applied on a surface of the one or more particulate nitrogen sources, and wherein the dry, flowable fertilizer composition comprises a non-clumped one or more particulate nitrogen sources; and wherein the dry, flowable fertilizer composition has a crush strength ranging from 7.0 to 7.85 when stored at 25° C. or 50° C. for 24 hours. 
 
     
     
       2. The dry, flowable fertilizer composition of  claim 1 , wherein the solid coating composition further comprises a second solvent, wherein the second solvent comprises one or more solvents selected from the group consisting of (a) one or more aprotic solvents and (b) one or more protic solvents. 
     
     
       3. The dry, flowable fertilizer composition of  claim 1 , wherein the solid fertilizer composition further comprises one or more members selected from the group consisting of surfactants, buffers, fragrance/odor masking agents, colorants, micro-nutrients, and flow modifiers, wherein the composition does not comprise water and alcohol. 
     
     
       4. The dry, flowable fertilizer composition of  claim 1 , wherein the solid coating composition further comprises colorants to enhance visual conformation of evenness of coating of the one or more particulate nitrogen sources surfaces and depth of penetration into the one or more particulate nitrogen sources. 
     
     
       5. The dry, flowable fertilizer fertilizer composition of  claim 1 , wherein the one or more particulate nitrogen sources are selected from the group consisting of a) urea, b) urea, formaldehyde reaction products, c) urea, formaldehyde, ammonia reaction products, d) manure, e) dicyandiamide, and f) compost, and wherein the composition weight percent comprises about 93.05-99.91% of said one or more particulate nitrogen sources. 
     
     
       6. The dry, flowable fertilizer composition of  claim 5 , wherein the one or more particulate nitrogen sources comprise urea. 
     
     
       7. The dry, flowable fertilizer composition of  claim 1 , wherein the solid fertilizer composition further comprises one or more flow modifiers selected from the group consisting of silicas, hydrophobized silicas, soaps, inorganic powders, and nonionic surfactants, wherein the flow modifiers comprise between about 0.25-3.5 percent weight of the dry, flowable fertilizer composition. 
     
     
       8. The dry, flowable fertilizer composition of  claim 1 , wherein the dry, flowable fertilizer composition comprises urea as the one or more particulate nitrogen sources and DMSO at weight percent range of between about 0.005 to about 0.2%. 
     
     
       9. A dry, flowable fertilizer composition comprising a) urea, b) a solid coating composition applied to the urea as a heated liquid at a temperature ranging from 40° C. to 70° C., wherein the solid coating comprises DMSO, and c) N-(n-butyl) thiophosphoric triamide (NBPT), wherein the DMSO is at a weight percent range of between about 0.005 to about 0.2% of the dry, flowable fertilizer composition, and the dry, flowable fertilizer composition has a crush strength ranging from 7.0 to 7.85 when stored between 25° C. to 50° C. for 24 hours. 
     
     
       10. The dry, flowable fertilizer composition of  claim 1 , wherein the dry, flowable fertilizer composition comprises less than 0.0789 wt % DMSO in the coating and one or more particulate nitrogen sources. 
     
     
       11. The dry, flowable fertilizer composition of  claim 10 , wherein the dry, flowable fertilizer composition comprises a percent increase in crush strength ranging from about 8% to about 45% over untreated urea when stored between 25° C. to 50° C. for  24  hours. 
     
     
       12. The dry, flowable fertilizer composition of  claim 1 , wherein the dry, flowable fertilizer composition comprises a percent increase in crush strength ranging from about 8% to about 45% over untreated urea when stored between 25° C. to 50° C. for  24  hours. 
     
     
       13. The dry, flowable fertilizer composition of  claim 1 , wherein N-(n-butyl) thiophosphoric triamide (NBPT) comprises at least 80% by weight of said coating composition. 
     
     
       14. The dry, flowable fertilizer composition of  claim 1 , wherein N-(n-butyl) thiophosphoric triamide (NBPT) comprises at least 85% by weight of said coating composition. 
     
     
       15. The dry, flowable fertilizer composition of  claim 1 , wherein the solid coating composition is exposed to a temperature range of 50-70° C., wherein the degradation of NBPT is 0.0% over a 900-3600 seconds of exposure. 
     
     
       16. A fertilizer composition comprising:
 a) one or more particulate nitrogen sources; and 
 b) a heated coating composition having a chill point ranging from 45° C. to 56° C. applied on the one or more particulate nitrogen sources that forms a solid coating on the one or more particulate nitrogen sources post-application and cooling, wherein 
 the heated coating composition comprises:
 i) N-(n-butyl) thiophosphoric triamide (NBPT) ranging from 75% to 95% by weight of said coating composition and 
 ii) dimethyl sulfoxide (DMSO) ranging from 4% to 24% by weight of the coating; and 
 the composition has a crush strength ranging from 7.0 to 7.85 when stored between 25° C. to 50° C. for 24 hours.